A managed currency is a currency for which the exchange rate is controlled by a government. The government does so by either setting a fixed exchange rate or by engaging in buying and selling transactions through its central bank. Even when a government claims to be letting its currency's exchange rate rise and fall in accordance with the forces of supply and demand, it may be making occasional interventions to stymie unusual exchange rate fluctuations. Some currency management is considered normal, in order to stabilize markets.